Where to get 5v for MAP for FAST install

Eric Stage I

TurboTweak Guy
May 25, 2001
I'm installing a FAST system right now. My 87 GN does not have the original dash, it has the GNX-like VDO gauge setup, so it is not providing 5 volts to the MAP anymore. Where is an acceptable place to get 5 volts from?

The FAST system has a 5V regulated output on terminal E1 and its ground reference on pin E2. The MAP signal input is on pin A1.

You can chose one of the following points for interface:

stock ECU pin C14 or TPS pin 'A' - grey to MAP sensor pin 'A'

Reference -
stock ECU pin D12 or TPS pin 'C' - blk to MAP sensor pin 'C'

On most adapter harnesses they have used the MAF signal wire (center pin 'B' ) going to stock ECM pin B6 to bring the MAP signal wire in from the engine compartment. This way you place a jumper wire from the center pin 'B' of the MAP sensor plug to the MAF sensor wire 'B' - yellow.

Make sure you solder these connections properly. If this signal cuts out under boost you could cause serious damage.

If don't like the idea of soldering, crimping and jumpers :eek: we have a piggyback plug-in harness that will do this for you in the engine compartment. This can be made to order so that you may locate the MAP sensor in the location of your choosing. :D

I would not recommend using anything other than the ECU running the engine for the 5V reference. I would fully expect to see a difference of as much as 50 millivolts from one 5V supply to another, and that can be quite a difference in the MAP reading. As mentioned above by Jack, use pin E1 and E2 on the FAST ECU for the 5V and ground signals for the MAP and the TPS.